1. Field of the Invention
The present invention relates to a wire puller used for pulling wires to set tight a linear object such as an electric wire.
2. Description of the Background
A method of set tight an overhead wire between utility poles etc. firstly secures a body of the wire puller described in Japan Utility Model H5-25819 to an utility pole, then couples the wire puller to a wire grip via a wire etc. so that the coupled wire grip can grip a free end of the overhead wire. Then, the method includes operating a ratchet handle of the wire puller body and winding the wire etc. on the wire puller body so that the free end of the overhead wire is pulled toward the utility pole and supported.
That is, it is necessary for a wire puller to wind a wire etc. connected with a wire puller to pull the overhead wire and it requires all the parts of the wire puller to have high rigidity because a strong reaction force against the pulling is applied to the wire puller at the time of the winding. In order to have high rigidity required for each member of the wire puller, the wire puller should also inevitably be heavy. However, workers pull wires by hands in a high place such as a top part of the utility pole and thus the increase in weight of the wire puller may lead to lowering their work efficiency.
Practically, construction work of an overhead wire attaches a wire puller and a wire grip to an utility pole, grips the overhead wire by the wire grip, hauls the wire grip gripping the overhead wire by the wire puller, and sets tight the overhead wire while pulling it. Therefore, the workers need to raise a heavy wire puller to the top part of the utility pole and also to work using the heavy wire puller on shaky scaffolding in a high place. The work using such heavy wire puller not only reduces the working efficiency but also involve much danger. For these reason, reduction in weight of a wire puller has been desired from a viewpoint of improvement in working efficiency and workers' safety.
FIG. 9 shows an example of a conventional wire puller. The wire puller shown in the FIG. 9 comprises a wire guide part (24) in nearly a horseshoe shape to guide the wire at the time of the winding so that the wire is uniformly wound. However, there was a problem that the number of parts and the number of assembly processes increased if the wire guide part was provided. Additionally, as reduction in weight of the wire puller have been required as mentioned above, an another problem was that the wire puller needed a wire guide part (24) and a joint to support the wire guide part, resulting in increase in weight of the wire puller.